Posted on 02/03/2004 2:37:14 PM PST by AdmSmith
The mystery of where Earth's first snakes lived as they were evolving into limbless creatures from their lizard ancestors has intrigued scientists for centuries. Now, the first study ever to analyze genes from all the living families of lizards has revealed that snakes made their debut on the land, not in the ocean. The discovery resolves a long-smoldering debate among biologists about whether snakes had a terrestrial or a marine origin roughly 150 million years ago--a debate rekindled recently by controversial research in favor of the marine hypothesis.
In a paper to be published in the 7 May 2004 issue of the Royal Society journal Biology Letters, Nicolas Vidal, a postdoctoral fellow, and S. Blair Hedges, a professor of biology at Penn State, describe how they put the two theories to the test. They collected the largest genetic data set for snakes and lizards ever used to address this question. Their collection includes two genes from 64 species representing all 19 families of living lizards and 17 of the 25 families of living snakes.
Genetic material from some of the lizards was difficult to obtain because some species live only on certain small islands or in remote parts of the world. "We felt it was important to analyze genes from all the lizard groups because almost every lizard family has been suggested as being the one most closely related to snakes. If we had failed to include genes from even one of the lizard families, we could have missed getting the right answer," Hedges explains.
"For the marine hypothesis to be correct, snakes must be the closest relative of the only lizards known to have lived in the ocean when snakes evolved--the giant, extinct mosasaur lizards," Vidal says. "While we can't analyze the genes of the extinct mosasaurs, we can use the genes of their closest living cousins, monitor lizards like the giant Komodo Dragon," he explains.
The team analyzed gene sequences from each of the species, using several statistical methods to determine how the species are related. "Although these genes have the same function in each species--and so, by definition, are the same gene--their structure in each species is slightly different because of mutations that have developed over time," Vidal explains. When the genetic comparisons were complete, Vidal and Hedges had a family tree showing the relationships of the species.
"Our results show clearly that snakes are not closely related to monitor lizards like the giant Komodo Dragon, which are the closest living relatives of the mosasaurs--the only known marine lizard living at the time that snakes evolved," Vidal says. "Because all the other lizards at that time lived on the land, our study provides strong evidence that snakes evolved on the land, not in the ocean."
The research suggests an answer to another long-debated question: why snakes lost their limbs. Their land-based lifestyle, including burrowing underground at least some of the time, may be the reason. "Having limbs is a real problem if you need to fit through small openings underground, as anybody who has tried exploring in caves knows," Hedges says. "Your body could fit through much smaller openings if you did not have the wide shoulders and pelvis that support your limbs." The researchers note that the burrowing lifestyle of many other species, including legless lizards, is correlated with the complete loss of limbs or the evolution of very small limbs.
This research was supported by the National Aeronautics and Space Administration Astrobiology Institute and the National Science Foundation.
(Excerpt) Read more at science.psu.edu ...
Finally a point on which we agree. He understands our frailty and human faults. All He requires is that we believe that Jesus died for those faults and imperfections. He takes care of the rest.
Most definitely! LOL.
Oh yes, they find a way to say it is not literal and spend many words justifying that belief, but it still comes down to disputing what is written.
Now either the Bible is the true word of God or it isn't. It isn't a combination of both.
There are certain points of disagreement or interpretation that are valid because they are either unspoken or not exactly clear.
By the same token, much of it is clearly literal or clearly figurative and a simple understanding of the language in which the reader is reading doesn't leave a whole lot of interpretive freedom.
My reference to your needing proof was meant for the evolutionist or those who think that evolution and creation can be compatible. If you are not one of those, that doesn't apply to you.
Did God give you this amazing ability to read minds and divine people's "true" motives for their beliefs? Or are you pridefully presuming that if someone disagrees with you, it must be because they surrending to a deadly sin, and it can't possibly be for other reasons, like maybe they've given it a lot of thought and study and that's their considered opinion on the matter?
That's just like the truth of Hank. It's not "my" knowledge, it's Hank's truth. Why? Because Hank says so.
I can't possibly take any personal responsibility for the decision of whether the information about Hank is completely true or not, so it's not "my" knowledge or conclusions at all, is it?
Um, or is it?
So when Jesus is taken to the mountaintop for where he can see all the kingdoms of the earth -- this is literal or figurative? Why? Would your opinion be based on knowledge available to those who first heard this story?
Gee, I haven't heard that one before. Quite creative (no pun intended).
Zulu, you seem as if you are not particularly settled with your beliefs and nothing I say is going to change that. I hope you straighten it all out eventually.
I am tired of repeating myself here and need to move along. I usually avoid these threads because they all end up the same way.
I suppose I fell into this because I have recently seen many blessings in my life and I felt like maybe I needed to spend some time defending God and what I believe His words to say.
I never had any delusions of softening the hearts of those who either don't believe in God at all or those that want to restrict Him to only attributes that can be explained by man.
I know that He understands that and it is really all that matters.
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